code: def test_output(self):
      with testing.assert_warns(UserWarning):
          self.expect(self.model, [self.x, self.rois])
  
file_path: chainer/tests/onnx_chainer_tests/functions_tests/test_poolings.py
imports: import chainer
  import chainer.functions
  from chainer import testing
  import numpy
  from onnx_chainer.testing import input_generator
  from onnx_chainer_tests.helper import ONNXModelTest
label_desc: Use image node_id 2 for calling the TestROIPooling2D obj's underlying member method code with example usage: obj.test_output() without return types